EP1265967A2

EP1265967A2 - Aqueous coating material that can be hardened physically, thermally or thermally and with actinic radiation and the utilization thereof

Info

Publication number: EP1265967A2
Application number: EP01915178A
Authority: EP
Inventors: Egon Wegner; Stephan Schwarte; Frank Jansing
Original assignee: BASF Coatings GmbH
Current assignee: BASF Coatings GmbH
Priority date: 2000-02-02
Filing date: 2001-01-30
Publication date: 2002-12-18
Anticipated expiration: 2021-01-30
Also published as: CA2398782A1; JP2003522248A; US7297375B2; WO2001057142A2; CA2398782C; JP2014237838A; JP5677715B2; ATE331765T1; MXPA02005855A; US20030139512A1; AU2001242358A1; BR0107865A; DE10004494A1; ES2266174T3; WO2001057142A3; EP1265967B1; DE50110338D1

Abstract

The invention concerns an aqueous coating material that can be hardened physically, thermally or thermally and with actinic radiation, containing: A) at least one ionically and/or non-ionically stabilized polyurethane that is saturated, unsaturated and/or grafted with olefinically unsaturated compounds as binding agent; B) at least one coloring and/or effect-giving pigment and C) at least one colorless powder that is substantially inert, transparent or opaque in relation to the other components of the coating material and that has a mean particle size ranging from 1.0 to 10.0 νm, whose particles have a density ranging from 0.8 to 3.6 gcm-3. The invention also relates to the utilization of the aqueous coating material for the production of monolayer and multilayer coloring and/or effect-giving enamels for primed and unprimed substrates.

Description

Aqueous coating material curable physically, thermally or thermally and with actinic radiation and its use

The present invention relates to a new aqueous coating material based on polyurethane and its use for the production of single-layer and multi-layer color and / or effect coatings in automotive initial and refinishing, industrial painting, including coil coating and container coating, plastic coating and furniture coating.

Thermally curable aqueous coating materials which contain a wetting agent, a coloring and / or effect pigment and a saturated, unsaturated and / or grafted with olefinically unsaturated compounds, ionically and / or nonionically stabilized polyurethane based on aliphatic, cycloaliphatic, aliphatic-cycloaliphatic, aromatic, aromatic Contain aliphatic-aromatic and / or cycloaliphatic-aromatic polyisocanates, and the corresponding coatings are, for example, from the patent EP-A-0 089 497, DE-A-44 37 535, DE-C-197 22 862 or DE-A-196 45 761 known. These known aqueous coating materials, in particular the water-based paints, and the single- or multi-layer paint and / or effect coatings produced with them have very good application properties.

If the single-layer or multi-layer color and effect coatings produced from the known water-based paints contain effect pigments, in particular metallic pigments, so-called clouds, ie light-dark shades, can form. These are an indication of defects in the dispersion and / or orientation of the color and / or effect pigments, in particular the effect pigments, in the coating. Cloudy paintwork, however, is especially the case with particularly high-quality products that have large-area paintwork, such as Automobiles, generally not accepted, because such paint defects give the impression of poor quality of the overall product (e.g. automobile).

The object of the present invention is to provide a new thermally curable or thermally and with actinic radiation curable aqueous coating material which is very good as a water-based lacquer or as a solid-color topcoat for producing single-layer and multi-layer color and / or effect coatings which have a significantly reduced tendency to Show formation of clouds is suitable. In addition, the otherwise excellent application properties of the previously known water-based paints and solid-color topcoats should not be affected, but should be retained in their entirety. Last but not least, the formation of clouds should also be reduced when the new waterborne basecoats are overcoated with a wide variety of clearcoats.

Accordingly, the new physically, thermally and / or actinic radiation-curable aqueous coating material has been found

A) at least one saturated, unsaturated and / or grafted with olefinically unsaturated compounds, ionically and / or nonionically stabilized polyurethane as binder,

B) at least one coloring and / or effect pigment and

C) at least one colorless, compared with the other constituents of the coating material substantially inert, transparent or opaque powder which an average particle size of 1.0 to 10.0 microns, whose particles have a density from 0.8 to 3.6 like ^"";

contains and which is referred to below as "coating material according to the invention". Further objects according to the invention are evident from the description below.

In view of the prior art, it was surprising and unforeseeable for the person skilled in the art that the object on which the present invention is based could be achieved with the aid of the specially selected powder (C) to be used according to the invention. Rather, it was to be expected that the use of powders (C), the average particle size of which is in the order of the dry layer thickness of the basecoats or solid-color paints made from the coating materials of the invention, would have serious disadvantages, particularly with regard to the quality of the overall optical impression and the strength of the Interlayer liability.

The coating material according to the invention is physically curing.

In the context of the present invention, the term “physical hardening” means the hardening of a layer of a coating material by filming by release of solvent from the coating material, the connection within the coating via loop formation of the polymer molecules of the binders (for the term cf. Römpp Lexicon lacquers and printing inks , Georg Thieme Verlag, Stuttgart, New York, 1998, "Binders", pages 73 and 74. Or the filming takes place via the coalescence of binder particles (cf. Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York , 1998, "Hardening", pages 274 and 275. Usually no crosslinking agents are required for this purpose. If necessary, physical hardening can be supported by atmospheric oxygen, heat or by exposure to actinic radiation. The coating material of the invention is thermally curable. Here, it can be self-networking or externally networking.

In the context of the present invention, the term “self-crosslinking” denotes the property of a binder to undergo crosslinking reactions with itself. A prerequisite for this is that the binders already contain both types of complementary reactive functional groups which are necessary for crosslinking on the other hand, those coating materials, adhesives and sealing compounds are referred to in which one type of the complementary reactive functional groups is present in the binder and the other type is present in a hardener or crosslinking agent .. In addition, Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998, "Härtung", pages 274 to 276, in particular page 275, below.

The coating material according to the invention is curable thermally and with actinic radiation. If thermal and curing with actinic light are used together in one coating material, one also speaks of “dual cure” and “dual cure coating material”.

In the context of the present invention, actinic radiation means electromagnetic radiation, such as visible light, UV radiation or X-rays, in particular UV radiation, and corpuscular radiation such as electron beams.

The coating material of the invention is a one-component (IC) system.

Within the scope of the present invention, a one-component (IC) -

System to understand a thermally or thermally and with actinic radiation coating material, in which the binder and the

Crosslinking agents are present side by side, ie in one component. The prerequisite for this is that the two components only crosslink with one another at higher temperatures and / or when irradiated with actinic radiation.

The coating material of the invention can also be a two-component (2K) or multi-component (3K, 4K) system.

In the context of the present invention, this is to be understood as a coating material in which, in particular, the binder and the crosslinking agent are present separately from one another in at least two components, which are only combined shortly before application. This form is selected when the binder and crosslinking agent react with one another at room temperature. Coating materials of this type are used primarily for coating thermally sensitive substrates, in particular in automotive refinishing.

The coating material of the invention is aqueous. This means that its constituents are dissolved and / or dispersed in water or in a mixture consisting of water and minor amounts of at least one water-miscible organic solvent. Here, “minor amounts” are to be understood as amounts which do not destroy the aqueous nature of the mixture.

The constituent part of the coating material of the invention is powder (C). This is a uniformly composed powder (C), which means that its particles have the same material composition. Or it is a mixture of at least two powders (C). Which variant is preferred depends on the requirements that are made in individual cases on the coating material according to the invention. In most cases this is enough Use of a powder (C) to achieve the advantages of the invention.

The powder (C) to be used according to the invention is colorless. This means that it has no hue and no chroma, but only brightness. So it is white or has a shade of gray. But it is preferably white. In addition, reference is made to Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, Stuttgart, New York, 1998 »Unbuntpunkt«, page 590.

The powder (C) is transparent in the sense of glazing or opaque in the sense of opaque. Transparent powders (C) are preferably used.

The powder (C) is essentially inert. This means that it is only sparingly soluble or insoluble in water and in the organic solvents which may still be present in the coating material according to the invention within the period normally provided for the production, storage and processing of the coating material of the invention, no essential constituents of the coating material absorbed or flocculated, no chemical reactions or only very slow chemical reactions with essential components of the coating material occur, no chemical reactions between the essential components of the coating material are catalyzed and their properties are not or only very slowly changed by heat and / or actinic light.

The powder (C) has an average particle size of 1.0 to 10.0, preferably 3.0 to 7.5 and in particular 4.0 to 7.0 μm.

Advantageous powders (C) have a comparatively narrow particle size distribution.

This means that both the proportion of fine grain and coarse grain is comparatively low. Particularly advantageous powders (C) have a maximum Particle size below 12, preferably below 11 and in particular below 10 microns.

The particles of the present invention to be used in the powder (C) having a density of 0.8 to 3.6, preferably 0.9 to 3.4 preferably 1.0 to 3.2 and in particular 1.1 to 3.0 like ^"' .

Although particles with a lower density could also be used in individual cases, there is then the danger that these particles will float in the coating materials after prolonged storage. On the other hand, particles with a higher density could also be used in individual cases, but there is then the risk that the particles settle comparatively quickly when stored for a long time.

The particles of the powder (C) to be used according to the invention can be of any shape. According to the invention, it is advantageous if they have a spherical shape. In the context of the present invention, a spherical shape is to be understood as an essentially spherical shape. Examples of spherical shapes are spheres, egg-shaped particles, dodecahedra or icosahedra, which can also have certain irregularities.

Examples of suitable substances from which the particles or the powders (C) can consist are crosslinked or uncrosslinked, organic or organometallic polymers, inorganic minerals, salts or ceramic materials or organically modified ceramic materials or mixtures of these substances. Of these, the inorganic minerals are advantageous and are therefore used with preference. These can be natural and synthetic minerals.

Examples of the suitable minerals are silicon dioxide, aluminum silicates, calcium silicates, magnesium silicates, Calcium aluminum silicates, magnesium aluminum silicates,

Calcium magnesium silicates, calcium magnesium aluminum silicates,

Beryllium aluminum silicates, aluminum phosphate or calcium phosphate or mixtures thereof. Of these, silicon dioxide is particularly advantageous and is therefore used with particular preference in accordance with the invention.

The preparation of the powders (C) to be used according to the invention has no special features in terms of method, but is carried out with the aid of methods which are customary and known in the field of organic, organometallic or inorganic chemistry. For example, organic polymers can be produced, for example, by emulsion, dispersion or precipitation polymerization or by comminution, for example by grinding or spraying melts or solutions of polymers which have already been prepared. The inorganic particles can be generated, for example, by precipitation processes and / or comminution. In the case of ceramic materials, a green body, which may already have the desired powder form, is usually first produced and then fired.

If necessary, the surfaces of the particles are subjected to an aftertreatment, for example hydrophilization or hydrophobization. The aftertreatment must not, however, remove the inertness of the particles.

The powders (C) can be incorporated as such into the coating materials according to the invention provided that they are easily distributed and do not agglomerate. According to the invention, it is advantageous if the powders (C) are incorporated as powder pastes. Further advantages result if, as paste resins or rubbing resins, binders are used which are contained in the coating material according to the invention.

The content of the powders (C) in the coating materials according to the invention can vary very widely and depends primarily on the intensity of the light-dark Shades to be avoided and according to the given color of the coloring and effect coating, which is produced from the relevant coating material according to the invention. Preferably 0.09 to 5.0, preferably 0.12 to 3.5 and in particular 0.3 to 2.5% by weight, based in each case on the solids content of the coating material according to the invention, are used.

The further essential component of the coating material of the invention is at least one binder (A).

According to the invention, this is at least one saturated, unsaturated and / or grafted with olefinically unsaturated compounds, ionically and / or nonionically stabilized polyurethane (A).

Depending on the type of stabilization, the polyurethane (A) to be used according to the invention advantageously has an acid number or amine number of 10 to 250 mg KOH / g (ionic stabilization or nonionic plus ionic stabilization) or from 0 to 10 mg KOH / g (nonionic stabilization), an OH number of 30 to 350 mg KOH / g and a number average molecular weight of 1,500 to 100,000 daltons.

The polyurethane (A) can be produced in any way. It is preferably obtainable by producing a polyurethane prepolymer which contains at least one free isocyanate group in a first process step.

The polyurethane prepolymer is linear, branched or comb-like, but especially linear. The linear polyurethane prepolymer preferably contains two free isocyanate groups, in particular two terminal free isocyanate groups. The branched or comb-like polyurethane prepolymers preferably contain at least two, in particular more than two free isocyanate groups, terminal free isocyanate groups being preferred.

From a methodological point of view, the production of the polyurethane prepolymers to be used according to the invention has no special features, but instead takes place, for example, as in the patents DE-C-197 22 862, DE-A-19645 761, DE-A-44 37 535, EP-A-0 522 419 or EP-A-0 522 420, by reacting at least one polyisocyanate, in particular a diisocyanate, with at least one polyol, in particular a diol, the isocyanate component being used in molar excess, so that terminal free isocyanate groups result.

Diisocyanates are preferably used for the preparation of the polyurethane prepolymers, and polyisocyanates are optionally used in minor amounts to carry out branches. In the context of the present invention, minor amounts are to be understood as amounts which do not cause the polyurethane prepolymers to gel during their production. The latter can also be prevented by using small amounts of monoisocyanates.

Examples of suitable diisocyanates are isophorone diisocyanate (= 5-isocyanato-1-isocyanatomethyl-1, 3, 3-trimethyl-cyclohexane), 5-isocyanato-1 - (2-isocyanatoeth-l-yl) -l, 3,3-trimethyl -cyclohexane, 5-isocyanato-l- (3-isocyanatoprop-l-yl) -l, 3,3-trimethyl-cyclohexane, 5-isocyanato- (4-isocyanatobut-l-yl) -l, 3,3-trimethyl -cyclohexane, l-isocyanato-2- (3-isocyanatoprop-l-yl) - cyclohexane, l-isocyanato-2- (3-isocyanatoeth-l-yl) cyclohexane, 1-isocyanato-2- (4-isocyanatobut-l -yl) -cyclohexane, 1,2-diisocyanatocyclobutane, 1,3-

Diisocyanatocyclobutane, 1,2-diisocyanatocyclopentane, 1,3-

Diisocyanatocyclopentane, 1,2-diisocyanatocyclohexane, 1,3-diisocyanatocyclohexane, 1,4-diisocyanatocyclohexane, dicyclohexylmethane-2,4'-diisocyanate, trimethylene diisocyanate, tetramethylene diisocyanate, pentame ethylene diisocyanate, hexamethylene diisocyanate, ethyl ethylene diisocyanate,

Trimethylhexane diisocyanate, heptane methylene diisocyanate or diisocyanates, derived from dimer fatty acids, as sold by the Henkel company under the trade name DDI 1410 and described in the patents DO 97/49745 and WO 97/49747, in particular 2-heptyl-3,4-bis (9 - Isocyanatononyl) -l-pentyl-cyclohexane, or 1,2-, 1,4- or 1,3-bis (isocyanatomethyl) cyclohexane, 1,2-, 1,4- or 1,3-bis (2-isocyanatoeth -l- yl) cyclohexane, l, 3-bis (3-isocyanatoprop-l-yl) cyclohexane, 1,2-, 1,4- or 1,3-bis (4-isocyanatobut-l-yl) cyclohexane, liquid Bis (4-isocyanatocyclohexyl) methane having a trans / trans content of up to 30% by weight, preferably 25% by weight and in particular 20% by weight, as described in the patents DE-A-44 14 032, GB- A-1220717, DE-A-16 18 795 or DE-A-17 93 785; Tetramethylxylylidene diisocyanate (TMXDI® from CYTEC), tolylene diisocyanate, xylylene diisocyanate, bisphenylene diisocyanate, naphthylene diisocyanate or diphenylmethane diisocyanate.

Examples of suitable polyisocyanates based on the diisocyanates described above are polyurethane prepolymers containing isocyanate groups, which have been prepared by reacting polyols with an excess of at least one of the diisocyanates described above, and / or isocyanurate, biuret, allophanate, iminooxadiazinedione, urethane, Polyisocyanates containing urea and / or uretdione groups. Polyisocyanates are preferably used which have a statistical average of 2.5 to 5 isocyanate groups per molecule and viscosities of 100 to 10,000, preferably 100 to 5000 mPas. In addition, the polyisocyanates can be modified in a conventional and known manner to be hydrophilic or hydrophobic.

Mixtures of uretdione and / or are very particularly preferred

Polyisocyanates containing isocyanurate groups and / or allophanate groups based on the diisocyanates described above, as obtained by catalytic Oligomerization of diisocyanates using suitable catalysts are used.

Examples of suitable monoisocyanates are phenyl isocyanate, cyclohexyl isocyanate or stearyl isocyanate or vinyl isocyanate, methacryloyl isocyanate and / or 1- (1-isocyanato-l-methylethyl) -3- (l-methylethenyl) benzene (TMI® from CYTEC),

Examples of suitable polyols are saturated or olefinically unsaturated Polyesteφolyole, which by reaction of

optionally sulfonated saturated and / or unsaturated polycarboxylic acids or their esterifiable derivatives, optionally together with monocarboxylic acids, and

saturated and / or unsaturated polyols, optionally together with monools,

getting produced.

Examples of suitable polycarboxylic acids are aromatic, aliphatic and cycloaliphatic polycarboxylic acids. Aromatic and / or aliphatic polycarboxylic acids are preferably used.

Examples of suitable aromatic polycarboxylic acids are phthalic acid, isophthalic acid, terephthalic acid, phthalic acid, isophthalic acid or terephthalic acid monosulfonate, or halophthalic acids, such as tetrachloro- or tetrabromophthalic acid, of which isophthalic acid is advantageous and is therefore used with preference. Examples of suitable acyclic aliphatic or unsaturated polycarboxylic acids are oxalic acid, malonic acid, succinic acid, glutaric acid. Adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid or dimer fatty acids or maleic acid, fumaric acid or itaconic acid, of which adipic acid, glutaric acid, azelaic acid, sebacic acid, dimer fatty acids and maleic acid are advantageous and are therefore used with preference.

Examples of suitable cycloaliphatic and cyclic unsaturated polycarboxylic acids are 1,2-cyclobutanedicarboxylic acid, 1,3-

Cyclobutanedicarboxylic acid, 1,2-cyclopentanedicarboxylic acid, 1,3-

Cyclopentanedicarboxylic acid, hexahydrophthalic acid, 1, 3-cyclohexanedicarboxylic acid, 1, 4-cyclohexanedicarboxylic acid, 4-methylhexahydrophthalic acid, tricyclodecanedicarboxylic acid, tetrahydrophthalic acid or 4-methyltetrahydrophthalic acid. These dicarboxylic acids can be used both in their ice and in their trans form and as a mixture of both forms.

The esterifiable derivatives of the above-mentioned polycarboxylic acids, such as e.g. their mono- or polyvalent esters with aliphatic alcohols with 1 to 4 carbon atoms or hydroxy alcohols with 1 to 4 carbon atoms. In addition, the anhydrides of the above-mentioned polycarboxylic acids can also be used if they exist.

If appropriate, monocarboxylic acids can also be used together with the polycarboxylic acids, such as, for example, benzoic acid, tert-butylbenzoic acid, lauric acid, isononanoic acid, fatty acids of naturally occurring oils, acrylic acid, methacrylic acid, ethacrylic acid or crotonic acid. Isononanoic acid is preferably used as the monocarboxylic acid. Examples of suitable polyols are diols and triols, especially diols. In addition to the diols, triols are usually used in minor amounts to introduce branches into the polyol polyols.

Suitable diols are ethylene glycol, 1,2- or 1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, 1,2-, 1,3-, 1,4- or 1.5 Pentanediol, 1,2-, 1,3-, 1,4-, 1,5- or 1,6-hexanediol, hydroxypivalic acid neopentyl ester, neopentyl glycol,

Diethylene glycol, 1,2-, 1,3- or 1,4-cyclohexanediol, 1,2-, 1,3- or 1,4-cyclohexanedimethanol, trimethylpentanediol, ethyl butyl propanediol, the positionally isomeric diethyl octanediols, 2-butyl-2-ethyl propanediol-1, 3, 2-butyl-2-methylpropanediol-1, 3, 2-phenyl-2-methylpropane-diol-1, 3,

2-propyl-2-ethylpropanediol-1,3,2-di-tert. -buty lpropanediol- 1,3,

2-butyl-2-propylpropanediol-1,3,1-dihydroxymethyl-bicyclo [2.2.1] heptane,

2,2-diethylpropanediol-1,3,2-dipropylpropanediol-1,3,2-cyclohexyl-2-methylpropanediol-1,3,2-dimethylhexanediol-2,5,2,5 -Diethylhexanediol-2,5, 2-ethyl-5-methylhexanediol-2,5, 2,4-dimefhylpentanediol-2,4,

2,3-dimethylbutanediol-2,3,1,4-bis (2'-hydroxypropyl) benzene or 1,3-bis (2'-hydroxypropyl) benzene.

These diols can also be used as such for the production of the polyurethanes (A) to be used according to the invention.

Of these diols, hexanediol and neopentyl glycol are particularly advantageous and are therefore used with particular preference.

Examples of suitable triols are trimethylolethane, trimethylolpropane or glycerol, in particular trimethylolpropane.

The triols mentioned above can also be used as such for the production of the polyurethanes (A) to be used according to the invention (cf. patent specification EP-A-0 339 433). If necessary, minor amounts of monools can also be used. Examples of suitable monools are alcohols or phenols such as ethanol, propanol, n-butanol, sec-butanol, tert-butanol, amyl alcohols, hexanols, fatty alcohols, allyl alcohol or phenol.

The Polyesteφolyole can be carried out in the presence of small amounts of a suitable solvent as an entrainer. As an entrainer z. B. aromatic hydrocarbons, such as in particular xylene and (cyclo) aliphatic hydrocarbons, for. B. cyclohexane or methylcyclohexane used.

Further examples of suitable polyols are polyester diols which are obtained by reacting a lactone with a diol. They are characterized by the presence of hydroxyl groups and recurring

Polyester portions of the formula - (- CO- (CHR) _m - CH2-O -) - from. The index m is preferably 4 to 6 and the substituent R is hydrogen, an alkyl, cycloalkyl or alkoxy radical. No substituent contains more than 12 carbon atoms. The total number of carbon atoms in the substituent does not exceed 12 per lactone ring. Examples include hydroxycaproic acid, hydroxybutyric acid, hydroxydecanoic acid and / or hydroxystearic acid.

For the preparation of the polyester diols, the unsubstituted ### - caprolactone, in which m has the value 4 and all R substituents are hydrogen, is preferred. The reaction with lactone is started by low molecular weight polyols such as ethylene glycol, 1,3-propanediol, 1, 4-butanediol or dimethylolcyclohexane. However, other reaction components, such as ethylenediamine, alkyldialkanolamines or even urea, can also be reacted with caprolactone. Also suitable as higher molecular weight diols are polylactam diols which are prepared by reacting, for example, ### - caprolactam with low molecular weight diols. Further examples of suitable polyols are polyethene polyols, in particular with a number average molecular weight from 400 to 5000, in particular from 400 to 3000. Suitable polyether diols are, for example, polyether diols of the general formula H - (- O- (CHR ¹ ) ₀ -) _p OH, where the Substituent R ¹ = hydrogen or a lower, optionally substituted alkyl radical, the index o = 2 to 6, preferably 3 to 4, and the index p = 2 to 100, preferably 5 to 50. Linear or branched polyether diols such as poly (oxyethylene) glycols, poly (oxypropylene) glycols and poly (oxybutylene) glycols are mentioned as particularly suitable examples.

On the one hand, the polyether diols should not introduce excessive amounts of ether groups, because otherwise the polyurethanes (A) formed according to the invention to be used swell in water. On the other hand, they can be used in amounts which ensure the nonionic stabilization of the polyurethanes (A). They then serve as the functional nonionic groups (a3) described below.

The polyurethane (A) to be used according to the invention contains either

(al) functional groups which can be converted into cations by neutralizing agents and / or quaternizing agents and / or cationic groups,

or

(a2) functional groups which can be converted into anions by neutralizing agents and / or anionic groups,

and or (a3) nonionic hydrophilic groups.

Examples of suitable functional groups (a1) to be used according to the invention, which can be converted into cations by neutralizing agents and or quaternizing agents, are primary, secondary or tertiary amino groups, secondary sulfide groups or tertiary phosphine groups, in particular tertiary amino groups or secondary sulfide groups.

Examples of suitable cationic groups (a 1) to be used according to the invention are primary, secondary, tertiary or quaternary ammonium groups, tertiary sulfonium groups or quaternary phosphonium groups, preferably quaternary ammonium groups, quaternary phosphonium groups or tertiary sulfonium groups, but in particular tertiary sulfonium groups.

Examples of suitable functional groups (a2) to be used according to the invention, which can be converted into anions by neutralizing agents, are carboxylic acid, sulfonic acid or phosphonic acid groups, in particular carboxylic acid groups.

Examples of suitable anionic groups (a2) to be used according to the invention are carboxylate, sulfonate or phosphonate groups, in particular carboxylate groups.

Examples of suitable neutralizing agents for the functional groups (a1) which can be converted into cations are inorganic and organic acids such as sulfuric acid, hydrochloric acid, phosphoric acid, formic acid, acetic acid, lactic acid, dimethylolpropionic acid or citric acid.

Examples of suitable neutralizing agents for the functional groups (a2) which can be converted into anions are ammonia and ammonium salts, for example

Ammonium carbonate or ammonium bicarbonate, as well as airline, such as Trimethylamine, triefhylamine, tributylamine, dimethylaniline. Diethylaniline, triphenylamine, dimethyl hanolamine, diethylethanolamine, methyldiethanolamine, triethanolamine and the like. The neutralization can take place in the organic phase or in the aqueous phase. Dimethylethanolamine is preferably used as the neutralizing agent.

The total amount of neutralizing agent used in the coating composition according to the invention is selected so that 1 to 100 equivalents, preferably 50 to 90 equivalents, of the functional groups (a1) or (a2) of the polyurethane (A) to be used according to the invention are neutralized.

The introduction of hydrophilic functional (potentially) cationic groups (a1) into the polyurethane prepolymers takes place via the incorporation of compounds which contain at least one, in particular two, groups which are reactive toward isocyanate groups and at least one group capable of forming cations in the molecule; the amount to be used can be calculated from the desired amine number.

Suitable groups which are reactive toward isocyanate groups are, in particular, hydroxyl groups and primary and / or secondary amino groups, of which the hydroxyl groups are preferably used.

Examples of suitable compounds are 2,2-dimethylolethyl- or propylamine, which are blocked with a ketone, the resulting ketoxime group being hydrolyzed again before the formation of the cationic group (a1), or N, N-dimethyl-, N, N- Diethyl or N-methyl-N-ethyl-2,2-dimethylolethyl or - propylamine.

The introduction of (potentially) anionic groups (a2) into the

Polyurethane molecules are made by incorporating compounds that have at least one that is reactive toward isocyanate groups and one that is capable of forming anions Group contained in the molecule; the amount to be used can be calculated from the target acid number.

Examples of suitable compounds of this type are those which contain two groups which are reactive toward isocyanate groups in the molecule. Suitable groups reactive toward isocyanate groups are those described above. Accordingly, alkanoic acids with two substituents on the ### carbon atom can be used, for example. The substituent can be a hydroxyl group, an alkyl group or preferably an alkylol group. These alkanoic acids have at least one, generally 1 to 3 carboxyl groups in the molecule. They have 2 to about 25, preferably 3 to 10, carbon atoms. Examples of suitable alkanoic acids are dihydroxypropionic acid, dihydroxysuccinic acid and dihydroxybenzoic acid. A particularly preferred group of alkanoic acids are the ###, ### - dimethylolalkanoic acids of the general formula R ^ - C (CH2θH) 2COOH, where R ^ stands for a hydrogen atom or an alkyl group with up to about 20 carbon atoms. Examples of particularly suitable alkanoic acids are 2,2-dimethylol acetic acid, 2,2-dimethylol propionic acid, 2,2-dimethylol butyric acid and 2,2-dimethylol pentanoic acid. The preferred dihydroxyalkanoic acid is 2,2-dimethylolpropionic acid. Compounds containing amino groups are, for example, ###, ### - diaminovaleric acid, 3,4-diaminobenzoic acid, 2,4-diaminotoluenesulfonic acid and 2,4-diamino-diphenyl ether sulfonic acid.

Nonionic stabilizing poly (oxyalkylene) groups (a3) can be introduced into the polyurethane molecules as lateral or terminal groups. For example, alkoxypoly (oxyalkylene) alcohols with the general

Formula R ³ O - (- CH2-CHR ⁴ -O-) _r H in R ⁴ for an alkyl radical with 1 to 6

Carbon atoms, R ^{4 represents} a hydrogen atom or an alkyl radical having 1 to 6 carbon atoms and the index r represents a number between 20 and 75, can be used (cf. patent specifications EP-A-0 354 261 or EP-A-0 424 705).

Of these functional (potentially) ionic groups (a1) and (a2) and functional nonionic groups (a3), the (potentially) anionic groups (a2) are advantageous and are therefore used with particular preference.

The use of polyols, polyamines and amino alcohols leads to an increase in the molecular weight of the polyurethane prepolymers (A).

Suitable polyols for chain extension are polyols with up to 36 carbon atoms per molecule, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,2-butylene glycol, 1,6-hexanediol , Trimethylolpropane, castor oil or hydrogenated castor oil, di-trimethylolpropane ether, pentaerythritol, 1,2-cyclohexanediol, 1,4-cyclohexane dimethanol, bisphenol A, bisphenol F, neopentyl glycol, hydroxypivalic acid-neopentyl glycol ester, hydroxyethylated or hydroxypropylated bisphenol A, mixtures of these (see patent specifications EP-A-0 339 433, EP-A-0 436 941, EP-A-0 517 707).

Examples of suitable polyamines have at least two primary and / or secondary amino groups. Polyamines are essentially alkylene polyamines having 1 to 40 carbon atoms, preferably about 2 to 15 carbon atoms. They can carry substituents that have no hydrogen atoms that are reactive with isocyanate groups. Examples are polyamines with a linear or branched aliphatic, cycloaliphatic or aromatic structure and at least two primary amino groups.

As diamines are hydrazine, e ylenediamine, propylenediamine, 1,4-butylenediamine, piperazine, 1,4-cyclohexyldimethylamine, hexamethylenediamine

1,6, trimemymexamemylenediamine, methanediamine, isophoronediamine, 4,4'- Diaminodicyclohexylme han and aminoethylene ethanolamine. Preferred diamines are hydrazine, alkyl or cycloalkyl diamines such as propylene diamine and l-amino-3-aminomethyl-3,5,5-trimethylcyclohexane.

It is also possible to use polyamines which contain more than two amino groups in the molecule. In these cases, however - e.g. by using monoamines - make sure that no cross-linked polyurethane resins are obtained. Such useful polyamines are diethylenetriamine, triethylenetetramine, dipropylenediamine and dibutylenetriamine. An example of a monoamine is ethylhexylamine (cf. patent EP-A-0 089 497).

Examples of suitable amino alcohols are ethanolamine or diethanolamine.

The polyurethanes (A) to be used according to the invention can contain terminal and / or lateral olefinically unsaturated groups. Groups of this type can be introduced, for example, with the aid of compounds which have at least one isocyanate-reactive group, in particular hydroxyl group, and at least one vinyl group. Examples of suitable compounds of this type are trimethylolpropane monoallyl ether or

Trimethylolpropane mono (meth) acrylate.

The polyurethanes (A) to be used according to the invention can be grafted with ethylenically unsaturated compounds. Examples of suitable polyurethanes (A) to be used according to the invention, which are present as graft copolymers, are from the patents EP-A-0 521 928, EP-A-0 522 420, EP-A-0 522 419 or EP-A-0 730 613 known.

The production of the polyurethanes (A) to be used according to the invention has no special features in terms of method, but takes place in accordance with the customary and known methods as described in the prior art cited at the beginning.

The proportion of the polyurethanes (A) to be used according to the invention in the coating materials according to the invention can likewise vary extremely widely and depends primarily on the intended use of the

Coating materials. If the coating materials according to the invention are curable thermally or thermally and with actinic radiation, the content depends in particular on the functionality of the polyurethanes (A) with regard to the crosslinking reaction with the crosslinking agent (D). According to the invention, it is advantageous to use the amounts as described in the prior art cited at the beginning. 10 to 80, particularly preferably 15 to 70 and in particular 20 to 60% by weight, in each case based on the

Solid content of the coating material according to the invention used.

The third essential component of the coating material according to the invention is at least one coloring and / or effect-giving, in particular one effect-giving pigment (B).

The pigments (B) can consist of inorganic or organic compounds. The coating material of the invention, in particular the waterborne basecoat and solid-color topcoat according to the invention, spec. The waterborne basecoat according to the invention therefore ensures a universal range of use on account of this large number of suitable pigments (B) and enables a multitude of color tones and optical effects to be achieved.

Metal pigments such as commercially available aluminum bronzes, aluminum bronzes chromated according to DE-A-36 36 183, commercially available stainless steel bronzes and non-metallic effect pigments such as pearlescent or interference pigments can be used as effect pigments (B). In addition, Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998, pages 176, “Effect Pigments” and pages 380 and 381 “Metal Oxide Mica Pigments” to “Metal Pigments”.

Examples of suitable inorganic color pigments (B) are titanium dioxide, iron oxides, Sicotrans yellow and carbon black. Examples of suitable organic coloring pigments are thioindigo pigments indanthrene blue, cromophthal red, irgazine orange and heliogen green. In addition, Römpp Lexikon Lacke und Druckfarben, Georg Thieme Verlag, 1998, pages 180 and 181, "Iron Blue Pigments" to "Iron Oxide Black", pages 451 to 453 "Pigments" to "Pigment Volume Concentration", page 563 "Thioindigo Pigments" and See page 567 “Titanium dioxide pigments”.

The pigments (B) can be incorporated as such into the coating material according to the invention, provided that they are easily distributed and do not agglomerate and / or their shape, which is responsible for the optical effects, is not damaged or destroyed. According to the invention, it is advantageous if the pigments (B) are incorporated as pigment pastes. Further advantages result if, as paste resins or rubbing resins, binders are used which are contained in the coating material according to the invention.

The proportion of pigments (B) in the coating material according to the invention can vary extremely widely and is based primarily on the opacity of the pigments, the desired color and the desired optical effect. The pigments (B) in the coating material according to the invention are preferably in an amount of 0.1 to 50, preferably 0.5 to 45, particularly preferably 0.5 to 40, very particularly preferably 0.5 to 35 and in particular 0.5 to 30 wt .-%, each based on the solids content of the coating material according to the invention.

In addition to the components (A), (B) and (C) described above, the coating material of the invention can contain at least one solid, liquid or contain gaseous organic and / or inorganic, low and / or high molecular weight additive (D).

Examples of suitable additives (D) for coating materials according to the invention which are curable thermally and thermally and with actinic radiation are crosslinking agents (D) such as unblocked polyisocyanates, in particular the partially or completely blocked polyisocyanates described above. especially those derived from those described above, aminoplast resins, compounds or resins containing anhydride groups, compounds or resins containing epoxy groups.

Tris (alkoxycarbonylamino) triazines, compounds or resins containing carbonate groups, beta-hydroxyalkylamides and compounds having on average at least two groups capable of transesterification, for example reaction products of malonic acid diesters and polyisocyanates or of esters and partial esters of polyhydric alcohols of malonic acid with monoisocyanates, as described in the European patent EP-A-0 596 460. Such crosslinking agents are well known to the person skilled in the art and are offered by numerous companies as sales products.

Depending on the reactivity of the crosslinking agent (D), it can be added directly to the coating materials of the invention, resulting in a so-called one-component system. However, if it is a particularly reactive crosslinking agent (D), such as a polyisocyanate or an epoxide, this is generally added to the coating materials according to the invention shortly before use. The result is a so-called two or multi-component system.

If the coating materials according to the invention are to be curable not only thermally but also with actinic radiation (dual cure), they also contain customary and known additives (D) which can be activated with actinic radiation. UV light is particularly preferably used. Examples of more suitable Additives (D) which can be activated with actinic radiation are (meth) acrylic, allyl, vinyl or dicyclopentadienyl functional (meth) acrylate copolymers or polyether acrylates, polyester acrylates, unsaturated polyester acrylates, epoxy acrylates, urethane acrylates, amino acrylates, melamine acrylates, silicone acrylates or the corresponding methacrylates.

The coating material of the invention can also reactive thinner

(D) for thermal curing or for curing with actinic radiation.

Examples of suitable reactive diluents (D) for thermal curing are oligomeric polyols (D) which are obtained from oligomeric intermediates

Metathesis reactions of acyclic monoolefins and cyclic monoolefins are obtained and can be obtained by hydroformylation and subsequent hydrogenation; Examples of suitable cyclic monoolefins are cyclobutene, cyclopentene, cyclohexene, cyclooctene, cycloheptene, norbones or 7-oxanorbones; Examples of suitable acyclic monoolefins are contained in hydrocarbon mixtures which are obtained by cracking in petroleum processing (Cs cut); Examples of suitable oligomeric polyols to be used according to the invention have a hydroxyl number from 200 to 450, a number average molecular weight Mn from 400 to 1000 and a mass average molecular weight Mw from 600 to 1100;

Further examples of suitable polyols (D) are branched, cyclic and / or acyclic C ₆ -C ₆ alkanes which are functionalized with at least two hydroxyl groups, in particular diethyloctanediols.

Further examples of polyols (D) to be used are hyperbranched

Compounds with a tetrafunctional central group derived from ditrimethylolpropane, diglycerol, ditrimethylolethane, pentaerythritol, tetrakis (2-hydroxyethyl) methane, tetrakis (3-hydroxypropyl) methane or 2,2-bis- hydroxymethyl-butanediol- (1,4) (homopentaerythritol). These reactive diluents can be prepared by the customary and known methods of producing hyperbranched and dendrimeric compounds. Suitable synthesis methods are described, for example, in the patent specifications WO 93/17060 or WO 96/12754 or in the book by GR Newkome, CN Moorefield and F. Vögtle, "Dendritic Molecules, Concepts, Syntheses, Perspectives", VCH, Weinheim, New York, 1996 , described.

Low-molecular polyfunctional ethylenically unsaturated compounds are suitable as radiation-curable reactive diluents (D). Examples of suitable compounds of this type are esters of acrylic acid with polyols, such as neopentyl glycol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate or pentaerythritol tetraacrylate; or implementation products from

Hydroxyalkyl acrylates with polyisocyanates, especially aliphatic polyisocyanates.

In addition to the additives (D) described above or instead of these, the coating material of the invention may contain customary and known binders (D).

Examples of common and known binders (D) are oligomeric and polymeric, linear and / or branched and / or block-like, comb-like and / or randomly constructed poly (meth) acrylates or acrylate copolymers, in particular those described in the patent DE-A-197 36 535, DE-A-44 37 535 or DE-A-197 41 554; Polyesters, in particular those described in the patents DE-A-40 09 858 or DE-A-44 37 535; Alkyds, acrylated polyesters, polylactones, polycarbonates, polyethers, epoxy resin-amine adducts, (meth) acrylate diols, partially saponified polyvinyl esters, or polyureas, of which the acrylate copolymers and / or the polyesters are particularly advantageous. Otherwise, the coating material according to the invention can contain customary paint additives as additives (D) in effective amounts. The type and amount of the additives (D) depend primarily on the intended use of the coating material of the invention.

Examples of suitable additives (D) are

organic and inorganic fillers such as chalk, calcium sulfate, barium sulfate, silicates such as talc or kaolin, silicas, oxides such as aluminum hydroxide or magnesium hydroxide, nanoparticles or organic fillers such as textile fibers, cellulose fibers, polyethylene fibers or wood flour;

UV absorbers;

Radical scavengers;

Crosslinking catalysts;

- slip additives;

polymerization inhibitors;

defoamers;

Emulsifiers, especially non-ionic emulsifiers such as alkoxylated alkanols and polyols, phenols and alkylphenols or anionic emulsifiers such as alkali salts or ammonium salts of alkane carboxylic acids, alkane sulfonic acids, and sulfonic acids of alkoxylated alkanols and polyols, phenols and alkylphenols; Wetting agents such as siloxanes, fluorine-containing compounds,

Carboxylic acid esters, phosphoric acid esters, polyacrylic acids and their copolymers or polyurethanes;

Adhesion promoters;

Leveling agents;

film-forming aids such as cellulose derivatives;

Flame retardants,

rheology-controlling additives, such as those known from the patent specifications WO 94/22968, EP-A-0 276 501, EP-A-0 249 201 or WO 97/12945; crosslinked polymeric microparticles, such as are disclosed, for example, in EP-A-0 008 127; inorganic layered silicates such as aluminum-magnesium silicates, sodium-magnesium and

Sodium magnesium fluorine lithium layered silicates of the

Montmorillonite type; Silicas such as aerosils; or synthetic polymers with ionic and / or associative groups such as

Polyvinyl alcohol, poly (meth) acrylamide, poly (meth) acrylic acid,

Polyvinylpyrrolidone, styrene-maleic anhydride or

Ethylene-maleic anhydride copolymers and their derivatives or hydrophobically modified ethoxylated urethanes or polyacrylates; or

water-miscible low and high-boiling organic solvents ("long solvents");

Photoinitiators, such as Norrish II-type photoinitiators, whose mechanism of action is based on an intramolecular variant of the

Hydrogen abstraction reactions are based in a variety of ways occur in photochemical reactions; As an example, reference is made here to Römpp Chemie Lexikon, 9th extended and revised edition, Georg Thieme Verlag Stuttgart, Vol. 4, 1991.

Further examples of suitable paint additives (D) are described in the textbook "Paint Additives" by Johan Bieleman, Wiley-VCH, Weinheim, New York, 1998.

From a methodological point of view, the production of the coating material according to the invention has no peculiarities, but takes place by dispersing its constituents in water, primary or secondary dispersion processes and customary and known mixing units such as stirred kettles, dissolvers, agitator mills or extruders being used. As an example, reference is made to the prior art cited at the beginning.

The coating material according to the invention, in particular the waterborne basecoat according to the invention, is outstandingly suitable for the production of color and / or effect multi-layer coatings on primed and unprimed substrates by the wet-on-wet method. Furthermore, the coating material of the invention, in particular the solid-color topcoat of the invention, is outstandingly suitable for the production of single-layer color and / or effect coatings.

Otherwise, the coating material of the invention can also be used as an adhesive or sealant or as a starting product for the production of self-supporting lacquer films.

The coating material of the invention exhibits particular advantages in its

Use as a water-based lacquer in the wet-on-wet process in which the water-based lacquer is applied to the primed or unprimed substrate and dried, but is not cured, after which it is applied to the water-based lacquer layer applied a clear lacquer and the resulting clear lacquer layer together with the water-based lacquer layer thermally or thermally and with actinic radiation (dual cure).

Suitable substrates are all surfaces to be painted which are not damaged by hardening of the layers thereon using heat or the combined use of heat and actinic radiation (dual cure); these are e.g. B. metals, plastics, wood, ceramics, stone, textiles, fiber composites, leather, glass, glass fibers, glass and rock wool, mineral and resin-bound building materials, such as plaster and cement boards or roof tiles, as well as composites of these materials. Accordingly, the multi-layer coatings according to the invention are also suitable for applications outside of the automotive OEM coating and automotive refinishing. They are particularly suitable for painting furniture and for industrial use, including coil coating and container coating. In the context of industrial applications, they are suitable for painting practically all parts for private or industrial use, such as radiators, household appliances, small parts made of metal such as screws and nuts, hubcaps, rims or packaging.

In the case of electrically conductive substrates, primers can be used which are produced in a customary and known manner from electrocoat materials (ETL). Both anodic (ATL) and cathodic (KTL) electrodeposition coatings, but especially KTL, come into consideration for this. Usually, especially in automotive painting, a filler paint or stone chip protection primer is applied to it, which can be regarded as part of the primer.

Primed or unprimed plastic parts made of e.g. B. ABS, AMMA, ASA, CA, CAB, EP, UF, CF, MF, MPF, PF, PAN, PA, PE, HDPE,

LDPE, LLDPE, UHMWPE, PC, PC / PBT, PC / PA, PET, PMMA, PP, PS, SB, PUR, PVC, RF, SAN, PBT, PPE, POM, PUR-RIM, SMC, BMC, PP-EPDM and UP (short names according to DLN 7728T1) can be painted, glued or sealed. In the case of non-functionalized and / or non-polar substrate surfaces, these can be subjected to a pretreatment, such as with a plasma or with flame treatment, or provided with a hydro primer in a known manner before the coating.

The application of the waterborne basecoats according to the invention can be carried out by all customary application methods, e.g. Spraying, knife coating, brushing, pouring, dipping, watering, trickling or rolling. The substrate to be coated can rest as such, with the application device or system being moved. However, the substrate to be coated, in particular a coil, can also be moved, the application system being stationary relative to the substrate or being moved in a suitable manner.

Spray application methods are preferably used, such as, for example, compressed air spraying, airless spraying, high rotation, electrostatic spray application (ESTA), optionally combined with hot spray application such as, for example, hot air - hot spraying. The application can be carried out at temperatures of max. 70 to 80.degree. C. are carried out so that suitable application viscosities are achieved without the water-borne basecoat and its overspray, which may need to be reprocessed, changing or being damaged by the briefly acting thermal load. For example, hot spraying can be designed in such a way that the water-based paint is heated only very briefly in or shortly before the spray nozzle.

It is particularly advantageous to apply the waterborne basecoat according to the invention pneumatically in a first application by ESTA and in a second application. If the water-based lacquers according to the invention contain constituents which can be activated with actinic radiation, the application is preferably carried out in the absence of light. Of course, these application methods can also be used for the application of the clear lacquer layer in the context of the wet-on-wet method according to the invention.

The hardening can take place after a certain rest period. It can have a duration of 30 s to 2 h, preferably 1 min to 1 h and in particular 1 min to 45 min. The rest period is used, for example, for the course and degassing of the paint layers or for the evaporation of volatile components such as solvents. The rest period can be supported and / or shortened by the use of elevated temperatures up to 90 ° C and / or by a reduced air humidity <10g water / kg air, in particular <5g / kg air, provided that no damage or changes to the paint layers occur, such as early full networking.

The physical hardening takes place already during the rest period and can be accelerated by the application of heat, whereby the methods used below in the thermal hardening can be applied.

The thermal hardening has no special features in terms of method, but takes place according to the customary and known methods such as heating in a forced air oven or irradiation with IR lamps. The thermal hardening can also be carried out in stages. The thermal curing is advantageously carried out at a temperature of 50 to 100 ° C., particularly preferably 60 to 100 ° C. and in particular 80 to 100 ° C. for a time of 1 minute to 2 hours, particularly preferably 2 minutes to 1 hour and in particular 3 min to 45 min. If substrates are used that can withstand high thermal loads, thermal crosslinking can also be carried out at temperatures above 100 ° C. In general, it is advisable not to exceed temperatures of 180 ° C., preferably 160 ° C. and in particular 155 ° C. Curing with actinic radiation also has no special features in terms of method, but is carried out in a customary and known manner by irradiation with UV lamps and / or electron beam sources, preferably under inert gas.

When the dual-cure water-based lacquer layers according to the invention are jointly hardened with the clear lacquer layers, the thermal hardening and hardening with actinic radiation can be used simultaneously or alternately. If the two curing methods are used alternately, thermal curing can be started, for example, and curing with actinic radiation can be ended. In other cases, it may prove advantageous to start and end the curing with actinic radiation. The person skilled in the art can determine the hardening method which is most advantageous for the individual case on the basis of his general specialist knowledge, if necessary with the aid of simple preliminary tests.

A further particular advantage of the waterborne basecoat according to the invention is that all customary and known clearcoats can be combined with the waterborne basecoat according to the invention in the wet-on-wet process.

Examples of suitable known one-component (IC), two-component (2K) or multicomponent (3K, 4K) clearcoats are known from the patents DE-A-42 04 518, US-A-5, 474,811, US-A-5,356,669, US -A-5,605,965, WO 94/10211, WO 94/10212, WO 94/10213, EP-A-0 594 068, EP-A-0 594 071, EP-A-0 594 142, EP-A-0 604 992, WO 94/22969, EP-A-0 596 460 or WO 92/22615.

One-component (IC) clearcoats are known to contain binders containing hydroxyl groups and crosslinking agents such as blocked

Polyisocyanates, tris (alkoxycarbonylamino) triazines and / or aminoplast resins. In In a further variant, they contain, as binders, polymers with pendant carbamate and / or allophanate groups and carbamate and / or allophanate-modified aminoplast resins as crosslinking agents (cf. US Pat. No. 5,474,811, US Pat. No. 5,356,669, US Pat. No. 5,605,965, WO 94 / 10211, WO 94/10212, WO 94/10213, EP-A-0 594 068, EP-A-0 594 071 or EP-A-0 594 142).

It is known that two-component (2K) or multicomponent (3K, 4K) clearcoats contain, as essential components, binders containing hydroxyl groups and polyisocyanates as crosslinking agents, which are stored separately until they are used.

Examples of suitable powder clearcoats are known, for example, from German patent specification DE-A-42 22 194 or the product information from BASF Lacke + Farben AG, "Powder coatings", 1990.

Powder clear lacquers are known to contain epoxy group-containing binders and polycarboxylic acids as crosslinking agents.

Examples of suitable powder slurry clearcoats are, for example, from US Pat. No. 4,268,542 and German patent applications DE-A-195

18 392.4 and DE-A-196 13 547 are known or are described in the unpublished German patent application DE-A-198 14 471.7.

Powder slurry clearcoats are known to contain powder clearcoats dispersed in an aqueous medium.

UV-curable clearcoats are known, for example, from the patents EP-A-0 540 884, EP-A-0 568 967 or US-A-4,675,234.

The thickness of the individual layers can vary widely within the multilayer coating according to the invention. According to the invention, however, it is advantageous if the water-based lacquer layer has a thickness of 5 to 25 μm, in particular 7 to 20 μm, and the clear lacquer layer has a thickness of 15 to 120 μm, preferably 30 to 80 μm and in particular 40 to 70 μm.

The single- and multi-layer coatings according to the invention have excellent optical, mechanical and chemical properties. So they are free from any surface defects such as shrinking. They also have a particularly high opacity and excellent optical effects, especially cloud-free metallic effects.

Example and comparative experiments VI and V2

The production and use of an aqueous basecoat material (example) and two non-inventive ones

Waterborne basecoats (comparative experiment VI)

The following components were provided or produced for the example and the comparative experiments VI and V2:

1. Polyurethane dispersion (A):

The polyurethane dispersion (A) was prepared in accordance with the instructions given in German Patent DE-A-44 37 535 on page 7, lines 21 to 34, “B Preparation of an Aqueous Polyurethane Dispersions”. The solids content of the dispersion was 31% by weight. %

Secondary aqueous acrylic dispersion: The secondary aqueous acrylate dispersion was prepared as described in the German patent specification DE-A-44 37 535 on page 8, lines 25 to 49, “E preparation of an aqueous polyacrylate dispersion”. The solids content of the dispersion was 40% by weight. %.

3. Aqueous solution of a polyester:

The aqueous solution of a polyester was, as in that in the German

Patent specification Patent specification DE-A-44 37 535 on page 7, lines 6 to 19, "A preparation of an aqueous polyester resin solution", specified specification and adjusted with water to a solids content of 60% by weight.

4. Rheological aids:

3% aqueous suspension of a synthetic layered silicate; Laponite® RD from Laporte.

5. Metallic pigment paste:

6.0 parts by weight of a 65% suspension of aluminum flakes (Aluminum Stapa Hydrolux® from Eckart) were mixed with 6.5 parts by weight of butyl glycol and 2.1 parts by weight of the aqueous solution of the polyester according to para. 3. homogenized.

6. Melamine resin solution:

Maprenal® VMF 3924 (70%) from Clariant.

7. Neutralizing agent:

10% aqueous solution of Dimethyleώanolarnin. 8. Wetting agent:

Commercial wetting agent from Air Products (50% in butyl glycol).

9. Silicon dioxide paste to be used according to the invention:

30 parts by weight of the aqueous solution of the polyester according to para. 3, 46 parts by weight of butyl glycol, 12 parts by weight of water and 12 parts by weight of a silica powder micron average particle size of 5.8 and a density of the particles of 2.1 liked ^"3 were mixed together and homogenized.

10. Solvent-polyester mixture of silicon dioxide paste

example 1

For example 1, 30 parts by weight of the rheology aid according to para. 3. submitted. For this purpose, 27 parts by weight of the polyurethane dispersion of para. 1., 3.0 parts by weight of the polyester solution according to para. 3., 6.0 parts by weight of the secondary aqueous acrylate dispersion according to para. 2nd, 2.1 parts by weight of butyl glycol, 6.0 parts by weight of melamine resin according to para. 6, 0.3 parts by weight of neutralizing agent according to para. 1., 1.5 parts by weight of the wetting agent according to para. 8 and 6.0 parts by weight of deionized water were added. The resulting mixture was homogenized and in the order given with 3.0 parts by weight of the silicon dioxide paste to be used according to the invention in accordance with para. 9 and with 14.6 parts by weight of the metallic pigment paste according to para. 5. offset.

The resulting waterborne basecoat was treated with the neutralizing agent according to para. 7. adjusted to a pH of 7.8 to 8.2 and with deionized water to a viscosity of 70 to 80 mPas with a shear of 1000 s ^"1 . Comparative experiment VI

Example 1 was repeated, except that no silicon dioxide paste according to para. 9 was applied.

Comparative experiment V2

Comparative test VI was repeated, except that 2.64 parts by weight of the solvent / polyester mixture of the silicon dioxide paste according to para. 10 were added.

For the testing of the application properties of the water-based paints, test boards measuring 30 x 70 cm were produced in a customary and known manner. For this purpose, steel panels (body panels), which were coated with a customary and known cathodically deposited and baked electro-dip coating, were coated with a commercially available filler from BASF Coatings AG), after which the resulting filler layer was kept at 20 ° C and a relative air humidity of 65 for five minutes % flashed off and baked in a forced air oven at 140 ° C for 30 minutes.

After the test panels had cooled to 20 ° C, the waterborne basecoats were applied in two spray passes. The first order was made using ESTA (bell speed: 45,000 rpm, steering air ESTA: 120 Nl / min, voltage: 65 kV, distance: 0.25 m, paint flow rate: 170 ml / min), corresponding to a dry film thickness of 8 to 10 microns. The second application was pneumatic (distance: 0.32 m, paint discharge: 540 ml / min, atomizing air - quantity: 300 Nl / min, atomizing air - pressure: 4.8 bar, horn air - quantity: 395 Nl / min, horn air - Pressure: 5.2 bar), corresponding to a dry film thickness of 4 to 6 μm. The waterborne basecoat was applied after the first and second application respectively flashed off for 2 min. The waterborne basecoat was then predried at 80 ° C. for 10 minutes, cooled and covered with a commercially available two-component clearcoat (from BASF Coatings AG). The water-based lacquer layer and clear lacquer layer were then baked at 130 ° C. for 30 minutes, which resulted in the effect-giving multi-layer coating of the example and the non-inventive multi-layer coating of comparative experiments VI and V2 with a dry film thickness of the clear coating of 40 μm.

The test panels were visually assessed and graded under diffuse light from a distance of 2 to 3 m in top view (80 °) and in oblique view (40 °) with regard to light-dark shading (clouds) (grade 1: no clouds visible; to Grade 5: Clouds very clearly visible).

In the example, the result was a grade of 2 in supervision and a grade 3 in oblique view. Comparative experiments VI and V2 each resulted in grade 4 in supervision and grade 5 in oblique view. This underpins that the use of silicon dioxide according to the invention results in a significant improvement the light-dark shading is achieved.

Claims

claims

1. Physically, thermally or thermally and with actinic radiation curable aqueous coating material containing

B) at least one coloring and / or effect pigment and

C) at least one colorless, transparent or opaque powder with an average particle size of 1.0 to 10.0 μm, which is essentially inert to the other constituents of the coating material, the particles of which preferably have a density of 0.8 to 3.6 ^"3 .

Aqueous coating material according to claim 1, characterized in that the powder (C) have an average particle size of 4.0 to 7.0 µm.

3. Aqueous coating material according to claim 1 or 2, characterized in that the particles like to have a density of 0.9 to 3.2 ^"3 .

4. Aqueous coating material according to one of claims 1 to 3, characterized in that the particles have a spherical shape.

5. Aqueous coating material according to one of claims 1 to 4, characterized in that the powder (C) has a maximum particle size below 12 microns.

6. Aqueous coating material according to any one of claims 1 to 5, characterized in that the particles consist of crosslinked or uncrosslinked, organic or organometallic polymers, inorganic minerals, salts or ceramic materials or organically modified ceramic materials or mixtures of these substances.

7. Aqueous coating material according to one of claims 1 to 6, characterized in that the particles of silicon dioxide, aluminum silicates, calcium silicates, magnesium silicates, calcium aluminum silicates, magnesium aluminum silicates, calcium magnesium silicates, calcium magnesium aluminum silicates, beryllium aluminum silicates,

Aluminum phosphate and / or calcium phosphate exist.

8. Aqueous coating material according to one of claims 1 to 7, characterized in that it contains the powder (C) in an amount of, based on the solids content, 0.09 to 5.0 wt .-%.

9. Use of the aqueous coating material according to one of claims 1 to 8 for the production of single-layer or multi-layer color and / or effect coatings for automotive initial and - repair painting, industrial painting, including coil coating and container coating, plastic painting and furniture painting ,

10. Use according to claim 9, characterized in that the aqueous coating material is used as a waterborne basecoat and solid-color topcoat in automotive initial and repair painting.

11. A process for producing a single- or multi-layered coloring and / or effect coating by applying at least one layer of the aqueous coating material according to any one of claims 1 to 8 to a primed or unprimed substrate and thermal curing or curing with heat and actinic light of the resulting

Wet layer (s).

12. Process for the production of a coloring and / or effect-giving multi-layer coating by the wet-on-wet method

(I) application of a waterborne basecoat to a primed or unprimed substrate,

(II) flashing off and intermediate drying of the resulting water-based lacquer layer,

(III) application of a clear coat on the water-based paint layer and

(IV) thermal curing or curing with heat and actinic light of the two wet layers,

characterized in that the aqueous coating material according to one of claims 1 to 8 is used as the water-based lacquer.